Method of making toric lenses and lens blanks



fg. menons `views of the blanks and molds illustrating the modifications of the blanks during fthe holding operation in Which- 'F'gure 1 is a longitudinal section of the blank as it leavesthe mold;

. Figure 2 is. a transverse sectional view thereof on the line 2-2 of Figure l;

Figure 3 is a longitudinal section of the Figure 4 is a transverse section thereof on the line 4 -4 of Figure 3; 1 o

Figure 5 is a longitudinal lsection of .the blank 'after leaving the mold, and

Figure 6 is a transverse section of the' same on the line (3*6 of Figure 5.

Similar reference numerals throughout the several -views indicate the same parts.

In the example shown, the lens blank irr-V dicated by A,'Figures 1 and 2, is molded or pressed so that. it will lia-ze an outer torc surface,- the longitudinal Vanis of which may, for purposes of illustration, bc considered as 6 di'opters, while the transyerse'afxis of this torio surface is4 of v8 diopters, the frcspe`ctive curves refcrrcdto being ind icatcd by the. corresponding numerals in F igurcs 1 and 2'.

The under surface of this blank has, We will say, as li-erical surface of l(5 (liopters'im dioated' y the numeral 6. in `each figure. The mold B, shown in section in Figure 3, has the longitudinal .meridian of its upper surface formed on a curve of 8 diopters, in-

' dicated by S, and as shown in Figure 4, the

transverse meridianv of .this mold surface is on a curve of G diopters indicated by 6". AThe blank shown in Figures 1 and 2, having been placed upon the top of Ithe mold B, as shown in dotted linesin Figures 3 and 4 is, with the mold, placed in a furnace and heated suliici-ently to allow the lens blank to soften sufficiently to drop into'contact with and conform to the surface of the mold.

Bv this means the Whole shape of the blank will be altered to that., as .shown in FiguresY 5 and 6, the -toric concave surface having its longitudinal` meridian onen 8 diopter curve and its transverse meridian on a. 6 dioptcr curve (see Figures 5 and 6) while the outer .surface Willbe approximately spherical and o-n `an 8 diopier spherical .curve as shownin saidgures. i 'I By the method described, a considerable economy in the production of the lenses is secured and the former tedious and expensive concave ltorio rough 'grinding is obviated.

I claim as my invention: 1. A method of forming torrie lenses com prising thefollowing steps (l) preparing a.-

concave surface (2) placing the Aconcave surq blanlgand heating the blank suiliciently face of `the mold.

a glass blank Vprovided with a concave groun and a toric sur-face'on the other, one of the 75 side and a tori-c convex surface on the other,

""of which corresponds to the spherical sur- 95 face of the blank (3) heating the hlanksu'li polishing the con-cave surface toren-rovescale 10D and polished 4spherical surface on' one side M and a torio vconvex Isurface on the'other, oneA of themendians of said tono surface'havm approximately the same curve as that of the face of the blank upon arnold-haring o. con- 4554 vex torio surface, one meridian of which cox-d respond-s to the spherical surface of the tocause it to cli-opinie contact-Vith the sur- 2. A inethod of forming torio lenses comprising the fol-lowing' steps .(1) preparinf' and polished spherical surface on one side mcridians :if said torio surface lmving` a)- proxinatcly the same curve as that of tie concave surface (2) placingthe concave snr-, 'face of the blankupon a :mold linfa-ing :i com'L rcx tor-ie surface,'tl1e transverse meridian B0 of -which corresponds to the spherical surface of the blank, and heating .the Ulan-l: suilciently to canse it to drop into contactu 'ith the surface of the mold. 3. A method vof forming .torio lenses coin- 85 prising the following 'steps (l) preparing a glass blank 'provided with a colmare 1 ground and -polished spherical surface on one one-.of the meridia-ns of said toric surface having approximately the suine curve as that of the concave surface, l'i-laciaig the' concave sui-'face .of the blank upon a lmeld having a convex torio surface, one 'meridian'Y ciently to cause it to drop intoconlaet with-` the surface o'i-the mold '4) grinding and polishing con-rcx surface o the llens and and mold marks. f J

4.- As an articleof niainl-facti-nfe a tol-ic 4 lens blank consisting -of a single piece of glass haring a convex spherical surface on one side and-son the opposite side a concave 10'5v torio surface, one .meridian only o-f said toiic surface correspond-ing with the ou'rve of vtheopposite spherical surface, the-said -s'pherical surface being ,a lio-wed surface and resulting' from heating and softcninf 'a glass blank" 1:10 .having a Aijnoldcd con-rex torio surface and a .spherical concave ground and poli-shed -surface 'while said concave surface is in Contact with the surface of a' mold having the desired toric form. f

annoncen B, masones. 2 

